I often monitor the weather fro the National Weather Service. For instance, go here: http://www.srh.noaa.gov/ifps/MapClick.php?CityName=Winder&state=GA&site=FFC

During the Summer and Winter months, the relative humidity outside is about the same. While it may feel dryer outside in colder months (like today) the humidity level shown is often higher than in the Summer months.

Now, I know my AC unit, when running in the Summer, will cause ambient moisture to condense and be drained out the condensation line/pump. This tells me moisture is being removed from inside the home. But, I have no visual indicator for the Winter months when moisture levels indoors seems a lot lower than in the Summer.

My only indicator of dryer air inside in the home during the Winter is that a) my skin and eyes are very dry, b) static electricity is much, much higher (so high that moving/touching electronics is a dangerous proposition–with deadly consequences), c) the trim-walls start cracking their caulked seams, etc.

I cannot just ‘stand there’ and not touch a ‘potential ground’ (wallplate screw at light switch, sink, my wife lol) and getting a large ZAP! A couple of years ago I accidentally destroyed an HDTV receiver when I went to move it from one room to another. I discharged myself before unplugging it, but as I walked from one room to the next I was very charge with static electricity and no real means but to stick a finger out and discharge myself. Unfortunately, this killed the receiver.

I cannot walk two feet with bedroom slipper or tennis shoes on without becoming charged. So, outside its +90% relative humidity and insude it feels like 3%. My forced hot air seems to do a wonderful job drying the air, even when we keep the thermostat relatively low (62-65ºF during daytime when we are there, 58-60 at night when we sleep), but the often-found cool/warm (or hot/cold) spots tell me that if I add a humidifier (or two) into the home this could lead to mold and mildew.

So, how would you handle this scenario? I have a five year old home that is two-story, open family room with zoned HVAC.